Noise and vibration mitigation system for nuclear reactors employing an acoustic side branch resonator

Abstract

A method of designing / making an acoustic side branch resonator structured to be coupled to a standpipe of, for example, a nuclear power plant, wherein the acoustic side branch resonator includes a plurality of wire mesh elements for damping purposes. The method includes determining a resonant frequency of the standpipe, determining an active length of the acoustic side branch resonator using the resonant frequency, and determining a particular number of the wire mesh elements to be used in the acoustic side branch resonator and a pitch of each of the wire mesh elements using momentum and continuity equations of a compressible fluid.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to nuclear power plants, such as, without limitation, boiling water reactor (BWR) type nuclear power plants, and in particular to a system for mitigating potentially damaging noise and vibration caused by the excitation of standing waves in closed side branches of a nuclear reactor system such as a BWR system as a result of steam flowing through the main steam line of the system.[0003]2. Description of the Related Art[0004]A BWR comprises a reactor vessel partially filled with water coolant which serves as a heat transfer medium. A reactor core containing nuclear fuel that generates heat is surrounded by the water coolant. A plurality of “jet” pumps are disposed within the vessel for increasing the velocity of the coolant through the reactor core in order to efficiently remove the heat generated by the nuclear fuel in the reactor core. The heat generated by the nuclear fuel is taken-up by t...

AI Technical Summary

Benefits of technology

The patent text describes a method and design for an acoustic side branch resonator that is used in a nuclear power plant. The resonator includes a housing and wire mesh elements that dampen sound waves. The method and design are based on the resonant frequency of the standpipe and the number and spacing of the wire mesh elements. The resonator is designed to match the impedance of the standpipe and to absorb and propagate the sound waves within a specific length. The technical effects of this invention include reducing the noise levels in the nuclear power plant and improving the overall performance of the acoustic resonator system.

Problems solved by technology

These acoustic standing waves create pressure fluctuations that propagate through the main steam line and cause degradation to the steam dryer and other equipment on the BWR, such as safety relief valves and turbine stop valves.

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